| 摘要 |
1,083,254. Moulding foamed synthetic resins. BOFORS-TIDAHOLMSVERKEN A.B. Oct. 22, 1964 [Oct. 23, 1963], No. 43175/64. Heading B5A. Foamed synthetic resin articles, in particular sheets of foamed polyurethane, are cast in a mould which comprises a base-plate 1, e.g. of laminated wood, and a vertically displaceable cover 3, e.g. of aluminium, the cover 3 being initially positioned to give a predetermined moulding volume equal to the volume of the starting materials to be introduced through a port 4, and being displaceable while remaining substantially parallel to base-plate 1 until the materials have expanded to a predetermined volume. The cover 3 is maintained parallel by spring-tensioned guides 8 fixed to beams 6a, the latter acting as stops for the cover. Brackets 5, having set-screws 5a, allow the initial position of cover 3 to be determined and the vertical displacement of the cover may be varied by attaching spacers to beams 6a. In an example, a polyol-isocyanate reaction mixture was formed by two jets directed towards one another, emission taking place under a pressure of 100 kg./cm.<SP>3</SP> from the nozzle of a mixing head placed in port 4. The moulding space was filled in about 6 seconds, the enclosed air being driven out between cover 3 and frame 2. After filling, port 4 was closed, 4-5 seconds later cover 3 began to rise, the cover being stopped by beams 6a after a further 8-10 seconds. To produce a lined product a sheet of wood fibre, plywood, steel, aluminium, glass fibre reinforced resin or tar paper may be placed on base-plate 1 prior to casting. An example of a profiled product is given where strips of foamed resin and wood are placed lengthwise and alternately against frame 2 between base 1 and cover 3, the wood strips being removed after casting to produce a comblike profile. |
